Zoonotic Cryptosporidium meleagridis in urban invasive monk parakeets.

Zoonotic Cryptosporidium meleagridis was identified in invasive monk parakeets (Myiopsitta monachus) from Santiago metropolis in Chile. Oocysts were isolated from nestlings' faeces, and a fragment of 18S ribosomal RNA gene was amplified and sequenced. This finding emphasizes the importance of permanent pathogen monitoring in synanthropic species with wide global distribution.

A Novel Dependoparvovirus Identified in Cloacal Swabs of Monk Parakeet (Myiopsitta monachus) from Urban Areas of Spain.

The introduction of invasive birds into new ecosystems frequently has negative consequences for the resident populations. Accordingly, the increasing population of monk parakeets (Myiopsitta monachus) in Europe may pose a threat because we have little knowledge of the viruses they can transmit to native naïve species. In this study, we describe a new dependoparvovirus detected by metagenomic analysis of cloacal samples from 28 apparently healthy individuals captured in urban areas of Madrid, Spain. The genomic characterization revealed that the genome encoded the NS and VP proteins typical of parvoviruses and was flanked by inverted terminal repeats. No recombination signal was detected. The phylogenetic analysis showed that it was closely related to a parvovirus isolated in a wild psittacid in China. Both viruses share 80% Rep protein sequence identity and only 64% with other dependoparvoviruses identified in Passeriformes, Anseriformes, and Piciformes and are included in a highly supported clade, which could be considered a new species. The prevalence was very low, and none of the additional 73 individuals tested positive by PCR. These results highlight the importance of exploring the viral genome in invasive species to prevent the emergence of novel viral pathogenic species.

Fine-scale genetic structure reflects limited and coordinated dispersal in the colonial monk parakeet, Myiopsitta monachus.

The genetic structure of animal populations has considerable behavioural, ecological and evolutionary implications and may arise from various demographic traits. Here, we use observational field data and molecular genetics to determine the genetic structure of an invasive population of monk parakeets, Myiopsitta monachus, at a range of spatial scales, and investigate the demographic processes that generate the observed structure. Monk parakeets construct large nests that can house several pairs occupying separate chambers; these nests are often aggregated within nesting trees. We determined patterns of relatedness within compound nests, within nesting trees and between trees. Spatial autocorrelation analyses of pairwise genetic relatedness revealed fine-scale genetic structure with relatives of both sexes spatially clustered within, but not beyond, nesting trees. In addition, males were more related to males sharing their compound nests than to other males occupying the same nesting tree. By contrast, males and females within compound nests were not significantly more closely related than elsewhere in the same tree, and we found no evidence for inbreeding. Adults showed high breeding site fidelity between years despite considerable disturbance of nest sites. Natal dispersal was female-biased, but dispersal distances were relatively short with some natal philopatry observed in both sexes. Sibling coalitions, typically of males, were observed amongst both philopatric and dispersing birds. Our results show significant clustering of kin within compound nests and nesting trees resulting from limited and coordinated natal dispersal, with subsequent breeding site fidelity. The resulting genetic structure has implications for social behaviour in this unusual parrot species.

Evolutionary History, Genomic Adaptation to Toxic Diet, and Extinction of the Carolina Parakeet.

As the only endemic neotropical parrot to have recently lived in the northern hemisphere, the Carolina parakeet (Conuropsis carolinensis) was an iconic North American bird. The last surviving specimen died in the Cincinnati Zoo in 1918 [1]. The cause of its extinction remains contentious: besides excessive mortality associated to habitat destruction and active hunting, their survival could have been negatively affected by its range having become increasingly patchy [2] or by the exposure to poultry pathogens [3, 4]. In addition, the Carolina parakeet showed a predilection for cockleburs, an herbaceous plant that contains a powerful toxin, carboxyatractyloside, or CAT [5], which did not seem to affect them but made the birds notoriously toxic to most predators [3]. To explore the demographic history of this bird, we generated the complete genomic sequence of a preserved specimen held in a private collection in Espinelves (Girona, Spain), as well as of a close extant relative, Aratinga solstitialis. We identified two non-synonymous genetic changes in two highly conserved proteins known to interact with CAT that could underlie a specific dietary adaptation to this toxin. Our genomic analyses did not reveal evidence of a dramatic past demographic decline in the Carolina parakeet; also, its genome did not exhibit the long runs of homozygosity that are signals of recent inbreeding and are typically found in endangered species. As such, our results suggest its extinction was an abrupt process and thus likely solely attributable to human causes.

Microsatellite characterisation and sex-typing in two invasive parakeet species, the monk parakeet Myiopsitta monachus and ring-necked parakeet Psittacula krameri.

Invasive species can have wide-ranging negative impacts, and an understanding of the process and success of invasions can be vital to determine management strategies, mitigate impacts and predict range expansions of such species. Monk parakeets (Myiopsitta monachus) and ring-necked parakeets (Psittacula krameri) are both widespread invasive species, but there has been little research into the genetic and social structure of these two species despite the potential links with invasion success. The aim of this study was to isolate novel microsatellite loci from the monk parakeet and characterise them in both monk and ring-necked parakeets in order to facilitate future investigations into their behaviour and population ecology. Sex-typing markers were also tested in both species. Of the 20 microsatellite loci assessed in 24 unrelated monk parakeets, 16 successfully amplified and were polymorphic displaying between 2 and 14 alleles (mean = 8.06). Expected heterozygosity ranged from 0.43 to 0.93 and observed heterozygosity ranged from 0.23 to 0.96. Nine of the 20 loci also successfully amplified and were polymorphic in the ring-necked parakeet, displaying between 2 and 10 alleles. Suitable markers to sex both species and a Z-linked microsatellite locus were identified. A multiplex marker set was validated for monk parakeets. These novel microsatellite loci will facilitate fine and broad-scale population genetic analyses of these two widespread invasive species.

Quantitative genetics in the monk parakeet (Myiopsitta monachus) from central Argentina: Estimation of heritability and maternal effects on external morphological traits.

The monk parakeet (Myiopsitta monachus) is a South American species unique among parrots; it builds communal stick nests that allow independence from tree or cliff cavities required by most parrots. As a very successful invasive species, it has expanded into several countries around the world. Questions remain around the factors that allowed this species to be such a successful invader in its native range as in other countries, and particularly the extent that evolutionary processes may be involved in adapting to new areas. Along with this line of analysis, we focused on assessing whether morphological characteristics are sufficiently heritable, and therefore responsive to selection. As the first step in this direction, we have estimated heritability of monk parakeet in six external morphological traits considered of potential adaptability value. Samples were obtained in the province of Córdoba in central Argentina. Data from seven microsatellites were used to determine the familial relationships among individuals. Heritabilities and genetic correlations were estimated by means of animal models. We found evidence for significant heritability in the six traits measured, particularly in weight, tarsus length and bill width. We also found evidence of maternal effects on morphological traits, particularly in the traits with lower heritability: wing length, bill length and tail length. Genetic correlations between traits were significant and associated with phenotypic correlations, suggesting that these traits are constrained in terms of evolutionary potential, whereas the amount of additive genetic variance in weight, tarsus length and bill width indicate that these traits could be responsive to selection.

Limited Dispersal and Significant Fine - Scale Genetic Structure in a Tropical Montane Parrot Species.

Tropical montane ecosystems are biodiversity hotspots harbouring many endemics that are confined to specific habitat types within narrow altitudinal ranges. While deforestation put these ecosystems under threat, we still lack knowledge about how heterogeneous environments like the montane tropics promote population connectivity and persistence. We investigated the fine-scale genetic structure of the two largest subpopulations of the endangered El Oro parakeet (Pyrrhura orcesi) endemic to the Ecuadorian Andes. Specifically, we assessed the genetic divergence between three sites separated by small geographic distances but characterized by a heterogeneous habitat structure. Although geographical distances between sites are small (3-17 km), we found genetic differentiation between all sites. Even though dispersal capacity is generally high in parrots, our findings indicate that dispersal is limited even on this small geographic scale. Individual genotype assignment revealed similar genetic divergence across a valley (~ 3 km distance) compared to a continuous mountain range (~ 13 km distance). Our findings suggest that geographic barriers promote genetic divergence even on small spatial scales in this endangered endemic species. These results may have important implications for many other threatened and endemic species, particularly given the upslope shift of species predicted from climate change.

Comparison of beak and feather disease virus prevalence and immunity-associated genetic diversity over time in an island population of red-crowned parakeets.

Pathogen outbreaks in the wild can contribute to a population's extinction risk. Concern over the effects of pathogen outbreaks in wildlife is amplified in small, threatened populations, where degradation of genetic diversity may hinder natural selection for enhanced immunocompetence. Beak and feather disease virus (BFDV) was detected for the first time in an island population of red-crowned parakeets (Cyanoramphus novaezelandiae) in 2008 on Little Barrier Island (Hauturu-o-Toi) of New Zealand. By 2013, the prevalence of the viral infection had significantly decreased within the population. We tested whether the population of red-crowned parakeets showed a selective response to BFDV, using neutral microsatellite and two immunity-associated genetic markers, the major histocompatibility complex (MHC) and Toll-like receptors (TLRs). We found evidence for selection at viral-associated TLR3; however, the ability of TLR3 to elicit an immune response in the presence of BFDV warrants confirmation. Alternatively, because red-crowned parakeet populations are prone to fluctuations in size, the decrease in BFDV prevalence over time may be attributed to the Little Barrier Island population dropping below the density threshold for viral maintenance. Our results highlight that natural processes such as adaptation for enhanced immunocompetence and/or density fluctuations are efficient mechanisms for reducing pathogen prevalence in a threatened, isolated population.

Ancestral origins and invasion pathways in a globally invasive bird correlate with climate and influences from bird trade.

Invasive species present a major threat to global biodiversity. Understanding genetic patterns and evolutionary processes that reinforce successful establishment is paramount for elucidating mechanisms underlying biological invasions. Among birds, the ring-necked parakeet (Psittacula krameri) is one of the most successful invasive species, established in over 35 countries. However, little is known about the evolutionary genetic origins of this species and what population genetic signatures tell us about patterns of invasion. We reveal the ancestral origins of populations across the invasive range and explore the potential influence of climate and propagule pressure from the pet trade on observed genetic patterns. Ring-necked parakeet samples representing the ancestral native range (n = 96) were collected from museum specimens, and modern samples from the invasive range (n = 855) were gathered from across Europe, Mauritius and Seychelles, and sequenced for two mitochondrial DNA markers comprising 868 bp of cytochrome b and control region, and genotyped at 10 microsatellite loci. Invasive populations comprise birds that originate predominantly from Pakistan and northern areas of India. Haplotypes associated with more northerly distribution limits in the ancestral native range were more prevalent in invasive populations in Europe, and the predominance of Asian haplotypes in Europe is consistent with the higher number of Asian birds transported by the pet trade outside the native range. Successful establishment of invasive species is likely to be underpinned by a combination of environmental and anthropogenic influences.

Shared genetic diversity across the global invasive range of the monk parakeet suggests a common restricted geographic origin and the possibility of convergent selection.

While genetic diversity is hypothesized to be an important factor explaining invasion success, there is no consensus yet on how variation in source populations or demographic processes affects invasiveness. We used mitochondrial DNA haplotypic and microsatellite genotypic data to investigate levels of genetic variation and reconstruct the history of replicate invasions on three continents in a globally invasive bird, the monk parakeet (Myiopsitta monachus). We evaluated whether genetic diversity at invasive sites could be explained by (i) the native source populations from which they were derived and (ii) demographic bottlenecks during introduction. Genetic data indicated a localized source area for most sampled invasive populations, with limited evidence for admixing of native source populations. This pattern largely coincides with historical data on pet trade exports. However, the invasive populations are genetically more similar than predicted from the export data alone. The extent of bottleneck effects varied among invasive populations. The observed low genetic diversity, evidence of demographic contraction and restricted source area do not support the hypothesis that invasion is favoured by the mixing and recombining of genetic variation from multiple source populations. Instead, they suggest that reduced genetic variation through random processes may not inhibit successful establishment and invasion in this species. However, convergent selection across invasive sites could also explain the observed patterns of reduction and similarity in genetic variation and/or the restricted source area. In general, the alternative explanation of intraspecific variation in invasive potential among genotypes or geographic areas is neglected, but warrants more attention as it could inform comparative studies and management of biological invaders.

Complete mitochondrial genome of endangered Socorro Conure (Aratinga brevipes) - taxonomic position of the species and its relationship with Green Conure.

Socorro Conure (Aratinga brevipes.Aratinga holochlora brevipes) is a parrot endemic to the Island of Socorro. According to some taxonomists the species is considered a subspecies of Green Conure (Aratinga holochlora). Some other classifications treat brevipes as a separate species based on relatively minor morphological differences between both species/subspecies. However, taxonomic position of Aratinga brevipes was never determined by molecular research. We sequenced full mitochondrial genome of the species and constructed phylogenetic tree using sequences of mitochondrial ND2 gene from A. brevipes and some other representatives of Conures group. Our results showed, that despite Aratinga brevipes is closely related to Aratinga holochlora, this Conure should be treated as a separate species.

Reproductive success depends on the quality of helpers in the endangered, cooperative El Oro parakeet (Pyrrhura orcesi).

In cooperative species, helping behaviour and reproductive success can be correlated, but understanding this correlation is often impaired by the difficulty to correctly infer causation. While helpers can incur costs by participating in brood care, it is yet unclear if their help depends on their individual quality. We address these questions in the previously unknown cooperative breeding system of the endangered El Oro parakeet (Pyrrhura orcesi). Specifically, we ask (i) whether breeders benefit directly from helpers by an enhanced reproductive success and if so, (ii) whether the amount of this potential benefit is regulated by the quality of contributing group members. Groups consist of a dominant breeding pair accompanied by helpers, but cooperation is not obligate. Microsatellite heterozygosity was used to assess individual quality; its suitability as indicator of quality was reflected in the positive relationship between offspring heterozygosity and recruitment into the population. The reproductive success of breeding pairs depended on helper (genetic) quality and the number of helpers. This relationship occurred on two different levels: clutch size and fledging success, indicating (i) that females profit from high-quality helpers and probably adjust clutch size accordingly and (ii) that the helpers increase fledging success. Congruently, we found that offspring body condition is positively affected by helper quality, which is most probably explained by the increased feeding rates when helpers are present. We suggest a causal link between cooperation and reproductive success in this frugivorous, endangered parakeet. Further, helper (genetic) quality can be a relevant factor for determining reproductive fitness in cooperative species, particularly in small and bottlenecked populations.

Complete mitochondrial genome of Blue-crowned Parakeet (Aratinga acuticaudata)--phylogenetic position of the species among parrots group called Conures.

Blue-crowned Parakeet (Aratinga acuticaudata) is a South American parrot species with a taxonomic position not confirmed by molecular studies. We sequenced full mitochondrial genome and constructed phylogenetic tree using sequences of mitochondrial ND2 gene from A. acuticaudata and some other representatives of Conures group. Our results confirmed previously described distribution of Aratinga species into three clades, but surprisingly did not classify Blue-crowned Parakeet to any of them. We found that A. acuticaudata shares the closest relationship with Diopsittaca nobilis and forms a separate clade together with Guaruba guarouba and Leptosittaca branickii species with a significant node. Our results confirm lack of monophyly of the genus Aratinga and underline the need of its taxonomic revision.

Species differences in early patterning of the avian brain.

The telencephalon is proportionately larger in parrots than in galliformes (chicken-like birds), whereas the midbrain tectum is proportionately smaller. We here test the hypothesis that the adult species difference in midbrain proportion is due to an evolutionary change in early brain patterning. In particular, we compare the size of the early embryonic midbrain between parakeets (Melopsittacus undulatus) and bobwhite quail (Colinus virgianus) by examining the expression domains of transcription factors Pax6 and Gbx2, which are expressed in the forebrain and hindbrain, respectively. Because these expression domains form rostral and caudal borders with the presumptive midbrain when this region is specified (Hamburger-Hamilton stages 9-11), they allow us to measure and compare the sizes of a molecularly defined presumptive midbrain in the two species. Based on published data from older embryos, we predicted that the molecularly defined midbrain territory is significantly larger in quail than parakeets. Indeed, our data show that normalized midbrain length is 33% greater in quail and that the midbrain to forebrain ratio is 28% greater. This is strong evidence of a significant species difference in early brain patterning.

Genetic evidence for high propagule pressure and long-distance dispersal in monk parakeet (Myiopsitta monachus) invasive populations.

The monk parakeet (Myiopsitta monachus) is a successful invasive species that does not exhibit life history traits typically associated with colonizing species (e.g., high reproductive rate or long-distance dispersal capacity). To investigate this apparent paradox, we examined individual and population genetic patterns of microsatellite loci at one native and two invasive sites. More specifically, we aimed at evaluating the role of propagule pressure, sexual monogamy and long-distance dispersal in monk parakeet invasion success. Our results indicate little loss of genetic variation at invasive sites relative to the native site. We also found strong evidence for sexual monogamy from patterns of relatedness within sites, and no definite cases of extra-pair paternity in either the native site sample or the examined invasive site. Taken together, these patterns directly and indirectly suggest that high propagule pressure has contributed to monk parakeet invasion success. In addition, we found evidence for frequent long-distance dispersal at an invasive site (approximately 100 km) that sharply contrasted with previous estimates of smaller dispersal distance made in the native range (approximately 2 km), suggesting long-range dispersal also contributes to the species' spread within the United States. Overall, these results add to a growing body of literature pointing to the important role of propagule pressure in determining, and thus predicting, invasion success, especially for species whose life history traits are not typically associated with invasiveness.

Genetic evidence links invasive monk parakeet populations in the United States to the international pet trade.

BACKGROUND: Severe ecological and economic impacts caused by some invasive species make it imperative to understand the attributes that permit them to spread. A notorious crop pest across its native range in South America, the monk parakeet (Myiopsitta monachus) has become established on four other continents, including growing populations in the United States. As a critical first step to studying mechanisms of invasion success in this species, here we elucidated the geographical and taxonomic history of the North American invasions of the monk parakeet. Specifically, we conducted a genetic assessment of current monk parakeet taxonomy based on mitochondrial DNA control region sequences from 73 museum specimens. These data supported comparative analyses of mtDNA lineage diversity in the native and naturalized ranges of the monk parakeet and allowed for identification of putative source populations. RESULTS: There was no molecular character support for the M. m. calita, M. m. cotorra, and M. m. monachus subspecies, while the Bolivian M. m. luchsi was monophyletic and diagnosably distinct. Three haplotypes sampled in the native range were detected within invasive populations in Florida, Connecticut, New Jersey and Rhode Island, the two most common of which were unique to M. m. monachus samples from eastern Argentina and bordering areas in Brazil and Uruguay. CONCLUSION: The lack of discrete morphological character differences in tandem with the results presented here suggest that M. m. calita, M. m. cotorra and M. m. monachus are in need of formal taxonomic revision. The genetic distinctiveness of M. m. luchsi is consistent with previous recommendations of allospecies status for this taxon. The geographic origins of haplotypes sampled in the four U.S. populations are concordant with trapping records from the mid-20th century and suggest that propagule pressure exerted by the international pet bird trade contributed to the establishment of invasive populations in the United States.

Comparative analysis of the prion protein open reading frame nucleotide sequences in peacock and parakeet.

The open reading frame of peacock and parakeet prion protein (PrP) genes was cloned and sequenced. The peacock and parakeet PrP genes consisted of 833 and 866 nucleotides encoding 266 and 277 amino acids, respectively (GenBank Accession numbers AY365065 and AY365066). Sequence analysis showed that the peacock and parakeet PrP genes had 93.67% homology to each other, 94.04% and 99.64% homology to the chicken PrP gene and 46.0% and 42.1% similarity to the mammalian PrP genes, respectively. The structural features of all known mammalian and avian PrPs, including N-terminal signal peptides, tandem repeats, conserved hydrophobic region, disulfide bridges and glycoinositol phospholipid anchor, were also found in peacock and parakeet PrPs. The parakeet and peacock PrPs, however, differed in the hexarepeat region, with the peacock having six and the parakeet having seven hexarepeats. The phylogenetic analysis showed that the PrP genes in 52 species were clustered into 2 distinct lineages, the avian and the mammalian. The peacock and parakeet PrP genes belonged to the same lineage but the peacock PrP was sub-classed with the pigeon PrP and the parakeet PrP was sub-classed with the duck and chicken PrPs. The present work added two more species data to the collection of the PrP genes and supported the previous findings that the PrP genes are highly conserved across species.

Molecular systematics in Aratinga parakeets: species limits and historical biogeography in the 'solstitialis' group, and the systematic position of Nandayus nenday.

The parrot genus Aratinga comprises 20 species that can be separated, based on morphological characters, in at least three distinct groups. We performed a phylogenetic analysis based on mtDNA sequences of individuals belonging to the solstitialis group with the objectives of: (1) assessing the genetic differences among individuals in order to clarify their specific status; (2) testing the monophyly of the group and establishing its phylogenetic position relative to other Aratinga species, (3) making inferences about temporal and geographical patterns of diversification in the Neotropics. As a result of the analysis, the three taxa belonging to the Aratinga solstitialis complex were found to be diagnosable phylogenetic species, the monotypic genus Nandayus was found to be included in the solstitialis group and the non-monophyly of the genus Aratinga was confirmed. Most of the speciation events occurred during the Pliocene and Pleistocene and may be related to habitat shifts associated to climate oscillation during these periods.